Corry returns to the England rank and file having led his country 14 times, including the demoralising autumn Test series when defeats against Argentina, South Africa and New Zealand ultimately cost head coach Andy Robinson his job.
But Fletcher said: "I don't think Martin has anything to prove at all. He has been an outstanding player for Leicester and England for a very long time.
"He has umpteen caps, a World Cup medal, countless Premiership titles and has been one of the top forwards in Britain for the past decade.
"Every time he pulls on a Leicester shirt he is a huge presence, so to say he has something to prove this weekend I don't think is true."
While 33-year-old Corry remains a key part of England's RBS 6 Nations Championship plans this season, his immediate task will be to plot a Leicester victory at Kingston Park that could take Tigers top of the Premiership.
And Leicester will encounter a Newcastle side whose erratic form was encapsulated over Christmas and new year when they followed up a 40-25 success against league champions Sale Sharks by crashing 42-15 at Harlequins just six days later.
Fletcher added: "I said last week that we had turned the corner, but it seems it was more of a roundabout.
"Leicester's strength in depth is at a different level to almost every side in the league, and they have a huge number of internationals in their squad.
"They are at a different stage in their development to us at the moment and that is where we aspire to be, so it will be a good test at the weekend."